Age-related reproductive performance and transcriptome profiling of testis in male blue catfish, Ictalurus furcatus

Catfish farming is the largest aquaculture industry in the U.S., where hybrid catfish produced by channel catfish, Ictalurus punctatus ♀ × blue catfish, I. furcatus ♂, represent >50% of the harvest. Typically, older blue catfish (≥5 years) are selected for artificial fertilization. However, observations at our facilities and reports from hatcheries indicate a high degree of variation in reproductive performance among individuals. Thus, it is essential to establish links between paternal age and reproductive success, as it is apparent that advanced paternal age leads to changes in reproductive performance. Since there are no prior studies regarding the changes in testis transcriptome in blue catfish males during aging, we evaluated global gene expression of testis at age 2,4,7 and 9. Significant differential expressed genes and gene ontology of pairwise comparisons between age 2 and each test age are presented and discussed. A total of 16 testis tissue samples from blue catfish males were used in this study, corresponding to ages 2, 4, 7 and 9. Age 2 was considered as the control group. Four testis tissue samples were collected per age group and extracted for RNA-seq.